The present invention relates to hydrocyclone separators and particularly to such separators for purifying liquid streams by removing solid particulate matter, such as sand, dust and other undesirable solid particles present in the liquid stream.
Hydrocyclone separators generally have the shape of a cone-shaped chamber having a tangential inlet duct, an upper fluid outlet and a bottom solid particle collector. A fluid stream is introduced through the inlet duct and flows spirally downwards the conical wall while increasing the spin velocity as it descends. Solid particles in the fluid such as sand or dirt are thrown against the wall of the chamber by centrifugal force resulting from the spiral rotation and are discharged at the outlet, at the bottom of die cone, into a collection chamber while the purified liquid moves upwards, at the center of die spiral, towards the outlet at the top of the chamber. Hydrocyclones are usually made of metal such as steel although stainless steel can also be used but it is rather expensive. A major problem with the hydrocyclone separators currently available is that as the solid particles increase their speed during their descent down the cone shaped wall, they increase the pressure and friction on die cone wall resulting in the erosion and abrasion of the metal wall. This is most evident near the bottom of the cone. The force of the particles as they scrape against the wall of die chamber varies, of course, depending on their concentration, hardness and sharp edges. Thus the bottom cone section, which takes die hardest beating, is often worn through until there are holes. Because of this erosion, the hydrocyclone separators frequently need repair, giving them a limited continuous life. When the erosion becomes severe enough, the whole unit is often replaced or dismantled and sent away for repair, or it is repaired on the spot by cutting away the cone bottom and welding on in its place another cone section or adding a patch by welding. During this repair period, which can take some time, the liydocyclone is out of service. For many applications the hyrdocyclone is used in the field away from maintenance shops and other repair facilities. In these cases tie problem of repairing hydrocyclones with eroded bottoms can be quite serious and expensive.
It is an object of the present invention to provide a new hydrocyclone separator giving greater resistance to erosion.
Another object of the present invention is to provide a hydrocyclone separator that can be repaired quickly when erosion does occur.
A further object of the invention is to provide a hydrocyclone separator having exchangeable conical bottom inserts.
A still further object of the invention is to provide a bottom insert for a conical hydrocyclone.
In accordance with the invention there is provided a hydrocyclone separator comprising a truncated cone-shaped vessel having a tangential fluid stream inlet, a fluid stream outlet, a solid particle collector and a conical insert removably mounted between the truncated cone-shaped vessel and the solid particle collector, said conical insert comprising an erosion resistant material.
The conical insert can be mounted between the truncated cone-shaped section of the vessel by means of mating flanges bolted or clamped together. The insert may be comprised of hard metal, metal oxide, hard rubber, or other synthetic abrasion resistant material. Alternatively, the insert may comprise a hard outer shell having an abrasion resistant inner lining which may be integral with the outer shell or merely supported by it.
In one preferred embodiment, the erosion resistant inner liner is a discrete separate unit that is supported by the insert and is easily replaceable when necessary.
Since the hydrocyclone separator of this invention comprises a removeable erosion resistant insert, any erosion occurring in the lower conical section will take place in the insert and can be dealt with quickly by exchanging the entire worn insert, or replacing the abrasion resistant liner with a new one. Preferably, the insert is mounted between two flanges connecting the body of the hydrocyclone with the precipitation collector without requiring special equipment, welding or other special complicated connecting means. Because the insert is lined or coated with an anti-erosion liner or coating, the down-time of tie hydrocyclone is substantially decreased.
The specific shape and cone angle of the insert can vary and may be designed to maximize the separation capabilities of the hydrocyclone, depending on the nature and composition of the fluid stream, die pressure differential in the hydrocyclone, and/or the draining of solid particulate matter into the particle collector to which the hydrocyclone is attached.